Semaphore safety-alarm.



No. 872,843. PATENTED DEG. 3, 1907.

G. L. PET T YGROVB.

'SEMAPHORE SAFETY ALARM.

APPLICATION FILED JULY 10. 1906.

% INVENTOR ATTORNEY tinrrnn srarns earnnr onnron GEORGE LESLIEPETTYGROYE, OF BERKELEY, CALIFORNIA, ASSIGNOR ONE-HALF TO C. E..LOOFBOURROW, OF OAKLAND OALIFORNIA.

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Specification of Letters Patent.

i 7 Application filed-Tilly I0, 1906. S'erialNo. 325.48%.

T 0 all whom it may concern:

' Beit'kn'own thatI, GEORGE LESLIE PET- TYGROVE, a citizen of the UnitedStates, and resident of Berkeley, county of Alameda, State ofCalifornia, have invented certain new and useful Improvements inSemaphore Safety-Alarms, of which the following is a specification.

In'the operation of railroad trains semaphores are extensively used topass and stop trains at stations. Two semaphore arms are usually.employed, one signaling to west bound trains, the other to east bound.

Both these arms are normallyset to the fjstop position, which is atright angles to the axis of the supporting pole; and trains are passedby lowering these arms so as to cause them to make an acute angle withthe lower part of the pole, the meaning of this position being clear. Athird position is provided for, inwhich the arm is raised to form anobtuse angle with the lower part of the supporting pole, the meaning ofthis position being proceed with caution; but this third signal isseldom used, and is taken no account of herein.

Semaphore arms are operated by levers working in slotted arcs situatedin a handy position for the operator. The levers nor mally stand uprightat the center of the arc, which maintains the semaphore arms in theirhorizontal stop position. Vii-hen approaching trains whistle for passingsignals if the operator he's no orders for them he throws theappropriate lever to clear, and returns it to stop as soon as the trainhas passed. But it sometimes happens that the operator under pressure ofbusiness forgets for the moment that he has orders for the particulartrain, and inadvertently displays the clear signal, only realizing hismistake when the train has passed beyond his control.

The object of my invention is to provide means of in the mind of theoperator the fact that orders are on hand for delivery, and to make thatfact the subject of his attention at the very instant when the questionof stop or clear is being settled by him. i

I attain my object by means illustrated in the accompanying drawing, ofwhich Figure 1 is a side elevation, partly in section, of the signallevers and arc of a seniaphore apparatus Fig. 2 is a plan view of same;Fig. 3 is a diagram of electrical connections, with a view of the springhooks for holding the train order clip boards.

Similar numerals of reference refer to similar parts throughout theseveral views. In general terms my invention consists in providing meansof giving to an operator at the instant that he moves a semaphore signalfrom its stop position, an audible alarm, whenever he has an undeliveredtrain order on hand; and of means of a'udibly impressing continuously onhis mind, when he is passing one train that should'properly be cleared,.

Patented Dec. 3, 1907.,

the fact that he has orders for other trains.

These-audible signals may be of any desired character; but those thatappear most suitable are avibrat-ing bell and a buzzer. The

bell and buzzer are so connected that they are both electricallyactuated by moving either lever off the stop position, wheneverundelivered train orders are on hand; and the buzzer alone is actuatedto give continuous warning, when, train order'sbeing on hand, trains arebeing properly cleared.

In detail my invention consists of the var'ious combinations andelements of'old and new character shown in the accompanying drawing, orrather of such novel parts thereof asare claimed in the subjoinedclaims.

1 is a lever operating the west arm of a semaphore apparatus, 2 a leveroperating the" east arm, and 3 the slotted arc aforesaid. I provide aplurality of hooks 4, 5, 6, adapted to suspend the clipboards 7, 8, 9,said clipboards securing the blanks used for copying train orders, saidhooks being movable to make and break electrical contacts. When all theclipboards are suspended from the hooks, the weight thereof keeps theelecti'ical contacts open; but when any one of said clipboards, as 7, isremoved, the contacts of said hookare closed by a spring 10 each of saidhooks beingsimilarly provided with a spring.

The spring hook cont-acts are in circuit with a bell l1 and a buzzer 12,and also with battery 13; and included in said circuits, in

springs shown at 20, 21, and 22.

, S eroaphore levers are equipped with' latches 23, 24, which enga enotches 25, 26, 27, m'the arc, to hold said evers in position.

- Tothese latches I attach devices 28, and 29',

adapted to act on buttons aforesaid-.bypressi them downward, andSeparating their contacts.

Referring now to the circuit diagram,

Fig. 3, and bearing inimind the-described ap- 10. I

paratus, the operation of my device 'Wlll readily be understood. Whenall the.clip-- boards are on their hooks,'which marks L a conditioncharacterized by theabsence of undelivered train orders, both the bellcircuit and the buzzer circuit are open at the hook contacts. The leversmay-therefore be oper- ;ated-in any desired manner without operating thealarm. But if a clipboard is removed from any one of the hooks, whichmarks a condition characterized by the presence of an undelivered trainorder a hook contact is closed. whereupon the movement of either buzzer.or both.

a lever, releasing the downward pressure on the arc buttons, closes, thebutton contacts, 25

and-closes thecircuit-through the bell, or the So, also, if either leveris-in the clear position, the removal of'a'clipboard willclose thebuzzercircuit, and thus admonish the "operator to adjust his sema- ,3o o

phore properly.

' Consider now the case of both levers being v in their upright, stopposition. Suppose the clipboard 7 is-ofi hook 4, and a train order isawaitingdelivery. If the'operator should move lever 1 fromitsuprightup'osition,circuits through belland'buzzer are completed.

I as follows: from battery 13 through closedcontacts of hook 4, to bell11, toi-closed con- H tacts of button- 15, to closedcontac't's of button 17, to battery; and from battery to closed contacts of hook 4,toibuzzer 12, to closed contacts of button 14, to battery. Consider wardpressure of device 28..

now the case of levers being in position circuits are open at hookcontacts. Remove clipboard 7 from hook and -a circuit is completedthrough buzzer,- through contacts" of book 4,. and contacts ofbutton 19;but the bell circuit is open at button 16 by down claim as new,and'desire to secure by Letters Patent of the United States, is: i

I shown in the drawing. Both bell and buzzer a x I H 'ving described vmyinvention, what I 1. A semaphore sa ety alarm comprising I thecombination-with a semaphore of an electrical alarmbell circuit and anelectrical alarm buzzer circuit, said circuits being normally open attwo, points, means of closing said circuits at one of the points by theact of removing a train order clipboard from its normal position, meansof closing said circuits at the other point by the act of moving saidsemaphore from its stop position,

and means of opening-said bell circuit by the act of setting thesemaphore to ,clear po-.

sition.

.2. 'In a semaphore safetyalarm, means for,

suspending train order clip-boards oompris- Q in'g movable hooks,electrical contacts thereon separable by the weight of said clipboards,and a spring on every hook adapted to clos'e'its contacts when aclip-board is removed.-

3."In-a semaphore safety alarm, a .semaphore lever, means 'forsignalingan imminent danger alarm and acautionary signal alarm

